78
C h a p t e r 8
Wiring External Modbus-compatible RS-232 Device
The TCU’s P-4 connector provides pins for connecting the TCU to an external RS-232 Modbus compatible device (see
table below for pin descriptions for connector P-4).
PIN #
Name
Description
P4-1
Unused
Reserved for future use; do not connect
P4-2
RS485_GND
RS-485 serial ground reference
P4-3
RS485_B
RS-485 serial interface B
P4-4
RS485_A
RS-485 serial inferface A
P4-5
SHIELD
Internally connected to chassis ground;
Cable shield for RS-485 or RS-232
P4-6
EX_GND_RAD
RS-232 signal ground
P4-7
RTS_RAD
RS-232 request to send
P4-8
EX_TXD_RAD
RS-232 transmit data to external device
P4-9
EX_RXD_RAD
RS-232 recieve data from external device
P4-10
CTS_RAD
RS-232 clear to send
In Figure 4, note that the RTS (request to send) and CTS (clear to send) connections are optional. They are only used for
master devices that require hardware handshaking.
Do not use the TCU to power an external RS-232 Modbus-compatible device (for example, a radio, modem, or
PLC). The device must be powered by a source other than the TCU.
Figure 4
Summary of Contents for TCU800
Page 1: ...Installation and Operation Manual T C U 8 0 0 Data Flow Systems Inc P r e l i m i n a r y ...
Page 2: ...Intentionally left blank ...
Page 4: ...D a t a F l o w S y s t e m s I n c Intentionally left blank ...
Page 8: ...ii Intentionally left blank ...
Page 10: ...ii Intentionally left blank ...
Page 56: ...46 C h a p t e r 5 Quick View Analog View Pump Statistics ...
Page 57: ...47 U s e r I n t e r f a c e Alarms Settings Screen 1 Settings Screen 2 ...
Page 58: ...48 C h a p t e r 5 Advanced Settings About ...
Page 77: ...67 O p e r a t i n g P r o c e d u r e s TCU Installed in Existing Control Panel ...
Page 87: ...77 M o d b u s S u p p o r t Figure 1 Figure 2 Figure 3 ...
Page 92: ...82 D a t a F l o w S y s t e m s I n c Appendix ...
Page 157: ...147 D a t a F l o w S y s t e m s I n c ...
Page 158: ...148 D a t a F l o w S y s t e m s I n c ...
Page 159: ...149 D a t a F l o w S y s t e m s I n c ...
Page 160: ......